Apparatus for stacking note books or the like

ABSTRACT

Apparatus for stacking pads with spiral binders has a reciprocable and pivotable turn-around device which inverts each second pad of a file of equidistant pads before the pads reach a stacking platform. At the stacking station, the pads are arrested by an adjustable stop which locates inverted pads in a first position and the non-inverted pads in a second position so that the binders of successive pads in a growing stack are located at the opposite sides of the stack. The turn-around device is arrested in response to detection of the absence of pads in the path along which the pads move toward the stacking platform by a photocell which further transmits signals to the mechanism for moving the stop so that the absence of one or more pads does not affect the array of pads in the stack on the platform. A level detector monitors the height of the stack on the platform and transmits signals for stepwise lowering of the platform. The number of pads in successive stacks is counted and the counter transmits signals which actuate a device for removing fully grown stacks from the platform.

This is a division of application Ser. No. 959,831, filed Nov. 13, 1978,now U.S. Pat. No. 4,268,200.

BACKGROUND OF THE INVENTION

The present invention relates to apparatus for accumulating stacks ofnote books, pads, pamphlets or analogous commodities includingoverlapping sheets which consist of paper or the like. Moreparticularly, the invention relates to apparatus for stacking groups ofsheets (hereinafter called pads for short) which issue from a producingor processing machine in a predetermined orientation, e.g., with theirbacks facing forwardly or backwards. Still more particularly, theinvention relates to improvements in apparatus for stacking pads or likesubstantially flat commodities whose thickness is not uniform throughoutso that, in the absence of remedial measures, the height of a stackwould vary from one side to the opposite side of the stack.

It is known to deliver a file of pads in identical orientation to astacking platform or table whereon successive pads are piled up on topof each other to form stacks of desired height. It is also known toequip such apparatus with stop means for arresting successive pads in apredetermined position in order to insure that each next-following padwill fully overlap the preceding pad. Fully grown stacks are transferredto a packing station or undergo further processing, for example, in aheating tunnel subsequent to introduction into envelopes consisting ofshrinkable synthetic plastic material which contracts in response to theapplication of heat and tightly surrounds the respective stack.

The just described mode of stacking pads or the like is satisfactory aslong as the thickness of each pad is constant throughout. In manyinstances, the thickness of at least one marginal portion of a padexceeds the thickness of other portions, e.g., because the pad isassembled of folded sheets whose backs overlie or are placed into eachother. Furthermore, the means for bonding or otherwise securing theleaves of pads to each other often or invariably contributes to greaterthickness of the corresponding portion of the pad. This appliesregardless of whether the sheets or leaves are held together by staples,stitches or, as in the case of certain types of steno pads, by helicalor otherwise configurated binders made of helically convoluted orcomb-shaped metallic or plastic wire. The accumulation of a relativelysmall number of such pads on top of each other results in the formationof a stack whose upper surface slopes from one marginal zone toward theopposite marginal zone. Therefore, the maximum permissible height ofsuch stacks is relatively small and the wrapping of stacks inheat-shrinkable plastic material or packing of stacks in crates, boxesor other types of containers presents many problems. A certain heightcannot be exceeded because the pads of a stack are likely to overturnwhich can cause lengthy delays and contributes to a pronounced reductionof the output of an automatic or semiautomatic stacking apparatus.

Attempts to overcome the just discussed problems in connection with thestacking of pads of varying thickness include the accumulation ofrelatively small stacks and the placing of two small stacks on top ofeach other so that the thicker portions of pads which form one of thesmall stacks are adjacent to one side and the thicker portions of padsconstituting the other small stack are adjacent to the opposite side ofthe resulting composite (higher) stack. Such procedure is acceptablewhen the thickness of one marginal portion of each pad exceeds onlyslightly the thickness of the remaining major portion of the same pad.However, the just discussed procedure is not acceptable when the leavesof pads are held together by binders whose diameters often greatlyexceed the thickness of the respective pile of sheets. The accumulationof relatively low stacks wherein the binders are superimposed upon eachother can result in pronounced instability of the stack and theconvolutions or prongs of neighboring binders are likely to becomeinterlaced to thus prevent orderly removal of pads from stacks.Therefore, pads wherein the leaves are held together by spirals orotherwise configurated binders are normally stacked by hand. Such modeof stacking is costly and time-consuming. Moreover, it is difficult tostack the pads by hand at the same rate at which they issue from ahigh-speed automatic or semiautomatic machine wherein the leaves of padsare connected to each other by spirals or otherwise configuratedbinders.

OBJECTS AND SUMMARY OF THE INVENTION

An object of the invention is to provide an apparatus which can neatlyand accurately stack pads or like commodities regardless of whether thethickness of certain portions exceeds the thickness of the remainingportion or portions of such commodities.

Another object of the invention is to provide an apparatus which isespecially suited for stacking of note books, pads and like commoditieswherein the leaves or sheets are held together by helical or otherwiseconfigurated binders whose diameters greatly exceed the thickness of thecorresponding piles of leaves.

A further object of the invention is to provide an apparatus which isconstructed and assembled in such a way that it can accumulate stackseach of which contains the same number of commodities regardless ofwhether or not the rate of delivery of commodities to the stackingstation is constant.

An additional object of the invention is to provide an apparatus whichis capable of accumulating relatively high stacks of pads or likecommodities even if one marginal portion of each commodity is muchthicker than the remaining portion or portions of the commodity.

A further object of the invention is to provide an apparatus which canrapidly accumulate identical stacks of pads or like commodities in afully automatic way and wherein the upper level of each stack ishorizontal or practically horizontal irrespective of variations in thethickness of commodities of which the stacks consist.

An additional object of the invention is to provide the apparatus with anovel and improved control system which monitors the delivery ofcommodities to be stacked and automatically regulates the operation ofstacking instrumentalities when the rate of delivery deviates fromnormal.

An ancillary object of the invention is to provide the apparatus withnovel and improved means for changing the orientation of selectedcommodities on their way to the stacking station.

The invention is embodied in an apparatus for manipulating substantiallyflat commodities, particularly for stacking pads each of which has afirst portion (e.g., a marginal portion containing a spiral or otherwiseconfigurated binder) whose thickness deviates from the thickness of atleast one second portion thereof. The apparatus comprises a verticallymovable platform or another suitable stacking device, a set of drivenendless flexible elements or other suitable means for transporting asuccession or commodities in identical orientation in a predetermineddirection and along a predetermined path on to the stacking device wheresuccessive commodities descend on top of each other to form a growingstack, stop means disposed above the stacking device and positioned toarrest successive commodities prior to descent onto the stacking deviceor on top of the growing stack on the stacking device, means for movingthe stop means between first and second positions, orientation changingmeans (e.g., a turn-around device which can invert a commodity through180 degrees) adjacent to the path ahead of the stacking device and beingactuatable to change the orientation of selected commodities in thepath, e.g., to invert each second commodity, means for actuating theorientation changing means, and control means for synchronizing theoperation of the actuating and moving means so that the stop meansassumes one of its positions prior to engagement with commodities whoseorientation remained unchanged and the other position prior toengagement with commodities whose orientation has been changed on theirway toward the stacking device. The control means preferably comprisesmeans (e.g., shift register means or another suitable time-delay device)for operating the moving means for the stop means with a delay uponinversion of each second commodity by the orientation changing means.

The apparatus further comprises a system of endless belts or othersuitable means for feeding commodities to the transporting means atregular intervals, and the control means preferably further comprisesmeans for monitoring the path and for generating signals in response todeviation of the intervals of feed of successive commodities from theaforementioned regular intervals (i.e., in response to detection of gapsin the file of commodities which are advanced toward the stackingdevice). The control means then further comprises means for interruptingthe operation of the moving means in response to such signals.

The actuating means for the orientation changing means may comprise aclutch, and the control means then comprises means for disengaging theclutch in response to detected absence of commodities in the path tothereby interrupt the actuation of the orientation changing means(provided, of course, that the orientation changing means was to beactuated in order to invert an oncoming commodity).

The novel features which are considered as characteristic of theinvention are set forth in particular in the appended claims. Theimproved stacking apparatus itself, however, both as to its constructionand its mode of operation, together with additional features andadvantages thereof, will be best understood upon perusal of thefollowing detailed description of certain specific embodiments withreference to the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a schematic elevational view of an apparatus for stacking padswhose leaves are held together by spiral binders which embodies one formof the invention;

FIG. 2 is an enlarged longitudinal vertical sectional view of theturn-around or orientation changing device in the apparatus of FIG. 1,the device being shown in one of its end positions corresponding to thatshown in FIG. 1;

FIG. 3 is a schematic elevational view of the turn-around device in theother end position; and

FIG. 4 is a circuit diagram of the control system in the apparatus ofFIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows an apparatus which serves to stack pads 104 of the typewherein the sheets or leaves are held together by means of spirals oranalogous binders 103. The manner in which the binders 103 areintroduced into the perforations of the leaves of pads 104 is disclosed,for example, in the commonly owned copending application Ser. No.854,818 filed Nov. 25, 1977, now U.S. Pat. No. 4,161,196 granted July19, 1979 to Paul Fabrig. Certain parts of the apparatus are denotedschematically by phantom lines; such parts include levers, links,connecting rods and similar standard parts of machines and apparatuswherein numerous components receive torque or another type of motionfrom a common prime mover or from two or more discrete prime movers. Theapparatus comprises a composite transporting unit 1 for pads 104, aturn-around or orientation changing device 2 which inverts each secondpad 104, a pad intercepting and transferring device 3 which cooperateswith an adjustable stop 4 to stagger successive pads 104 preparatory tostacking, a stacking platform 6 whereon the pads 104 are accumulated ontop of each other to form stacks of desired height, and a table 7 forreception of fully grown stacks of pads 104.

The transporting unit 1 comprises several endless flexible elements inthe form of belt conveyors 8 which are disposed in parallel verticalplanes (one behind the other, as viewed in FIG. 1) and are trained overpulleys 9, 11 to 14, 16 to 19 and 21 so as to advance along a relativelycomplex path a portion of which is variable and extends through theorientation changing or turn-around device 2. The pulley 18 is driven bythe main prime mover 24 of the apparatus (e.g., a variable-speedelectric motor) through the medium of a main drive shaft 23 and atransmission 22. The operative connection between the output element ofthe transmission 22 and the shaft for the pulley 18 is indicated by aphantom line 22A. The pulley 19 is adjacent to the driven pulley 18 andis mounted at the lower end of a lever 26 which is biasedcounterclockwise, as viewed in FIG. 1, by a spring 26A so as to tensionthe conveyors 8 in the region between the pulleys 18 and 21. The pulleys11, 12 and 13 can be said to form part of the turn-around device 2 thedetails of which are shown in FIGS. 2 and 3.

The turn-around device 2 comprises a reciprocable carriage 27 mounted onwheels or rollers 28, 29 which are guided in or on tracks defined by astationary guide 31 so that the carriage 27 is confined to reciprocatorymovements in directions indicated by a double-headed arrow 32. Thecarriage 27 is provided with a horizontal shaft 33 which extendstransversely of the direction of movement of pads 104 toward theintercepting device 3 and supports two pivotable arms 34 (only one shownin FIG. 2). The arms 34 are disposed at the outer sides of the twooutermost conveyors 8 and are connected to each other by traverses 36,37 so as to form therewith a swingable pocket 38 the deepmost portion ofwhich contains the pulley 12. The pulleys 11, 13 which, too, form partof the turn-around device 2 are also mounted in the space between thetwo arms 34. The pulleys 11, 12 and 13 cause the belt conveyors 8 toform loops which are open at 39, i.e., between the pulleys 11 and 13 soas to provide room for entry of each second pad 104. The deepmostportions of the loops which are defined by the conveyors 8 contain astop or abutment 41 which extends in parallelism with and in front ofthe pulley 12 and whose end portions are secured to the arms 34. Theshaft 33 is located in the region of the opening 39, i.e., between thepulleys 11 and 13.

The means for pivoting the pocket 38 about the axis of the shaft 33comprises a gear 42 which is fixedly secured to the shaft 33 and mesheswith a stationary toothed rack 43 so that the pocket 38 automaticallypivots back and forth (between the positions shown in FIGS. 2 and 3) inresponse to reciprocation of the carriage 27 along the guide 31.

The means for reciprocating the carriage 27 comprises a link 44 which isarticulately connected to the carriage and to one arm of a bell cranklever 47 mounted in a bearing 46 so as to be pivotable about a fixedhorizontal axis parallel to the axis of the shaft 33. The other arm ofthe bell crank lever 47 is articulately connected with a link 49 whichis coupled to the eccentric pin 51A of a rotary member 51 forming partof a crank drive 48. The member 51 is or comprises a gear meshing with asmaller gear 52 shown in FIG. 1. The smaller gear 52 can receive torquefrom the main drive shaft 23 by way of a transmission 54 which drivesthe input element of an electromagnetically operated clutch 53. Theradius of the gear 51 matches the diameter of the gear 52. Theconstruction of the clutch 53 is such that its input element can engagethe output element (which drives the gear 52) only after the inputelement completes a full revolution. The just described parts togetherconstitute an actuating unit 55 for the turn-around device 2.

Those portions of the conveyors 8 which are located immediately ahead ofthe intercepting device 3 travel below the lower reaches of a set ofoverhead belt conveyors 56 trained over pulleys 57 and 58. The pulley 58receives torque from the driven pulley 18 by way of a chain drive 59.The intercepting device 3 resembles a comb and is mounted on a secondcarriage or slide 61 which is reciprocable in directions indicated by adouble-headed arrow 62, i.e., in and counter to the direction ofmovement of pads 104 along the path which is defined by the transportingunit 1. The means 63 for reciprocating the slide 61 and for thus movingthe stop 4 between two end positions comprises a lever 66 which ispivotable about the axis of a fixedly mounted horizontal shaft 64 and isarticulately coupled to the slide 61 by a link 67. The lever 66 iscoupled to an eccentric pin 68A of a disk 68 driven by a transmission 69which receives motion from the main drive shaft 23.

The stop 4 is also a comb-like member and is movable between two endpositions by an electromagnet 71 (shown in FIG. 4) and a return spring126. This stop further serves as a means for stripping successive pads104 off the intercepting member 3. To this end, the prongs of the stop 4extend into and can pass through the gaps between the prongs of themember 3. The stacking platform 6, too, is a comb-like structure and theprongs which form its vertical or upright wall permit the passage ofprongs on a stack removing device here shown as a pusher 72 which ismovable in directions indicated by a double-headed arrow 74 to transfera fully grown stack of pads 104 from the horizontal base plate of theplatform 6 onto the horizontal base plate of the table 7. The upper partof the stack removing pusher 72 constitutes an auxiliary platform 73 forthe pads 104. The pusher is mounted on a carriage or trolley 76 which isreciprocable in directions indicated by the double-headed arrow 74. Themeans for reciprocating the carriage 76 (hereinafter called trolley tomore readily distinguish from the carriage 27) comprises a bell cranklever 78 which is pivotable about the axis of a fixedly mountedhorizontal shaft 77 and receives motion from a crank drive including aconnecting rod 79 which is coupled to one arm of the lever 78 and to aneccentric pin 81A of a disk 81 receiving torque from the main driveshaft 23 by way of a transmission 98 and a clutch 97. The disk 81 isrigidly connected to or integral with a cam 82 whose peripheral surfaceis tracked by a roller follower 83 on a lever 86 which is pivotableabout the axis of a fixedly mounted horizontal shaft 84. A rod 87connects the lever 86 with an endless chain 91 which is trained oversprocket wheels 88, 89 and is coupled to a vertically reciprocablesupport 92 for the platform 6. The sprocket wheel 89 can be engaged byan electrically operated brake 93 which receives signals from a circuit94 whose input is connected with a level detector 96 above the table 6.

The construction of the clutch 97 between the transmission 98 and thedisk 81 (and cam 82) is such that, when engaged, the clutch rotates thedisk 81 and cam 82 through one revolution and is automaticallydisengaged after its output element has rotated the parts 81 and 82through 360 degrees (clockwise, as viewed in FIG. 1).

The pulley 9 for the conveyors 8 is adjacent to and located slightlydownstream of a pulley 101 for a set of belt conveyors 102 which feedpads 104 from a machine of the type disclosed in the aforementionedcopending application Ser. No. 854,818 or from a similar machine. Forexample, the conveyors 102 can deliver pads 104 directly from thestation where the binders 103 are inserted into the perforations of theleaves of such pads and the end portions of the binders are bent in thecustomary way to form open or closed loops in order to reduce thelikelihood of injury to the user and/or of entanglement of neighboringbinders. As a rule, the belts 102 deliver at least one file ofequidistant pads 104 in identical orientation, e.g., with the binders103 located at the leading ends of successive pads and extendingtransversely of the direction of movement of the upper reaches ofconveyors 102 and 8.

The control system 106 which regulates the operation of the improvedapparatus by synchronizing the movements of certain parts which must beactuated in a given sequence and by interrupting the operation ofcertain parts in the event of a malfunction (e.g., in the absence of oneor more pads in the file of pads which is normally fed by the conveyors102) is shown in FIG. 4. This control system further comprises a signalgenerating device 107 (e.g., a reflection type photocell) which monitorsthe path of pads 104 upstream of the orientation changing or turn-arounddevice 2, e.g., between the pulley 9 and the device 2, and whose signalgenerating element transmits signals to a logic circuit 114 of the typeknown as inverter, to a pad counter 119 and to a time-delay device 118whenever a pad 104 advances therebelow. The control system 106 furthercomprises a pulse generator 108 including a disk 109 which is mounted onand is driven by the main drive shaft 23 and carries one or more magnets111 serving to induce a proximity detector 112 to transmit a signalwhenever a magnet advances therealong.

The output of the inverter 114 is connected with one input of an ANDgate 113 the other input of which is connected with the proximitydetector 112. The output of the AND gate 113 is connected with theclutch 53 by way of an amplifier 116. The just described partsconstitute a means 110 for disengaging the normally engaged clutch 53(i.e., a means for interrupting the operation of actuating means for thedevice 2) in response to detection of the absence of a pad 104 in thefile of pads which is normally transported by the conveyors 102 and 8 ontoward and past the turn-around device 2.

The proximity detector 112 further serves to transmit signaltransporting pulses to the stages of the aforementioned time-delaydevice 118 and a further time-delay device 117. Each of these time-delaydevices is a shift register with a predetermined number of stages. Theshift register 118 forms part of a unit 120 which energizes theelectromagnet 71 for the movable stop 4 at required intervals and withrequisite delay following inversion of each second pad 104 or interruptsthe energization of the electromagnet in response to detected absence ofone or more pads, and the shift register 117 forms part of an actuatingunit 150 which energizes the clutch 97 at required intervals. The firststage of the shift register 117 receives signals from the output c ofthe counter 119, and the first stage of the shift register 118 receivessignals directly from the photocell 107; the latter further transmitssignals to the input a of the counter 119. The signals which aretransmitted to the first stages of the shift registers 117, 118 aretransported from stage to stage by pulses which are generated by theproximity detector 112.

The counter 119 is adjustable and further comprises an erasing input bwhich is connected with its output c, i.e., the counter 119 is reset tozero whenever its output transmits a signal to the first stage of theshift register 117. The signal which reaches the last stage of the shiftregister 117 is transmitted to the clutch 97 by way of an amplifier 121.

The last stage of the shift register 118 is connected with the input aof a counter 122 whose output c transmits a signal in response toreception of two signals from the last stage of the shift register 118.The signal at the output c of the counter 122 is further transmitted toits erasing input b.

The output c of the counter 122 is connected with the dominant input aof a signal storing circuit 123 (e.g., a circuit of the type known asflip-flop) which further comprises an erasing input b connected with theoutput of the last stage of the shift register 118 and an output c whichcan transmit signals to the electromagnet 71 by way of an amplifier 124.

The movable stop 4 can constitute or is connected with the armature ofthe electromagnet 71 and is permanently biased to its left-hand endposition (as viewed in FIG. 4) by the aforementioned return spring 126.The bias of the spring 126 is overcome (i.e., the stop 4 is caused tomove to its right-hand end position) in response to energization of theelectromagnet 71 via amplifier 124.

It is equally within the spirit of the invention to simplify theconstruction of the energizing unit 120 for the electromagnet 71. Forexample, this electromagnet can be energized in direct response tosignals generated by a suitable device which monitors the operation ofthe turn-around device 2. Thus, the pocket 38 can generate a signal inone of its end positions, and such signal is transmitted with requisitedelay to energize or deenergize the electromagnet 71.

The operation is as follows:

The conveyors 102 deliver pads 104 at a predetermined frequency whichdepends on the rate of introduction of binders 103 into the stacks ofsheets or leaves to form pads 104 in the aforediscussed machine whichprecedes or includes the feeding conveyors 102. As a rule, the conveyors102 deliver a file of pads wherein the pads 104 are located at a fixeddistance from each other, and successive pads advance onto and with theupper reaches of the conveyors 8 by moving across the relatively narrowclearance between the pulleys 9 and 101. Successive pads 104 aredetected by the photocell 107 which, as shown in FIG. 4, transmitssignals to the inverter 114, to the input a of the adjustable counter119 and to the first stage of the shift register 118. The output of theinverter 114 does not transmit a signal when its input receives a signalfrom the photocell 107; therefore, the output of the AND gate 113normally does not transmit signals in spite of the fact that one inputof the gate 113 receives signals from the proximity detector 112, atleast once during each revolution of the main drive shaft 23.Consequently, the clutch 53 is normally engaged, i.e., the clutchremains engaged as long as the conveyors 8 receive pads 104 at regularintervals. This means that the crank drive 48 transmits motion to thecarriage 27 of the turn-around device 2 whereby the latter inverts eachsecond pad 104 but permits alternate pads 104 to pass the invertingstation without any change in orientation. The crank drive 48 causes thegear 42 to roll back and forth along the toothed rack 43 so that thepocket 38 pivots back and forth in synchronism with operation of theapparatus, i.e., at the rate which is determined by the RPM of the maindrive shaft 23. The arrangement is such that the openings 39 of loopsformed by those portions of the conveyors 8 which are trained over thepulleys 11, 12 and 13 face an oncoming pad 104 after a pad has advancedbeyond the turn-around device 2 without any change in its orientation.As shown in FIG. 3, each second oncoming pad 104 enters the pocket 38 tobe arrested by the abutment 41 short of the pulley 12, and such pad isthereupon turned through 180 degrees to the position shown in FIG. 1before it is permitted to leave the pocket 38 via openings 39 to move ontoward the gap between the conveyors 8 and 56. Pivoting of the pocket 38preferably takes place continuously, i.e., the pocket 38 can begin topivot from the position of FIG. 3 toward the position of FIG. 1 as soonas a pad has entered its interior to an extent which suffices to insurepredictable inversion. Analogously, the evacuation or expulsion of a pad104 from the pocket 38 can begin before the pocket reaches the positionof FIG. 1. The pad 104 which immediately follows an inverted pad travelsover the pulley 11 when the pivoting of the pocket 38 to the position ofFIG. 1 is completed or practically completed (or even while the pocket38 begins to pivot back toward the end position of FIG. 3). All thatcounts is to insure that each second pad 104 is inverted and that allother pads can advance over the turn-around device 2 without any orwithout appreciable change in their orientation. In the embodiment whichis illustrated in the drawing, the binders 103 of inverted pads 104 arelocated at the trailing ends of such pads and the binders 103 ofnon-inverted pads are located at the leading ends of the respective pads104 (note that the binder 103 of the pad 104 which is shown in FIG. 1immediately downstream of the pulley 9 is located at the leading end ofsuch pad). It is clear, however, that the apparatus will operateproperly if the conveyors 102 deliver pads 104 in such orientation thatthe binders 103 are located at their trailing ends.

The pads 104 which advance beyond the turn-around device 2 aretransported by the conveyors 8 with assistance from the conveyors 56 sothat they move over the stop 4 and descend onto the intercepting device3. The latter moves back and forth (arrow 62) because it is driven bythe reciprocating means 63, i.e., by the lever 66 and link 67. When thedevice 3 moves counter to the direction of delivery of pads 104 by theconveyors 8, it moves the intercepted pad 104 thereon against the stop 4which arrests the pad so that the device 3 moves relative to the pad andallows the latter to descend onto the platform 6 or onto the uppermostpad of the growing stack on the platform 6. The signal which isgenerated by the photocell 107 on detection of the just discussed pad isdelayed by the shift register 118 and reaches the input a of the counter122 and the input b of the flip-flop 123 when the corresponding padrests on the intercepting device 3. Since the output c of the counter122 transmits a signal to the input a of the flip-flop 123 in responseto transmission of the second one of two successive signals from thelast stage of the shift register 118, the counter 122 is reset to zeroand the dominant input a of the flip-flop 123 receives a signal inresponse to advancement of each second pad 104 past the photocell 107.Thus, the flip-flop 123 is set in response to each second signal fromthe photocell 107 and the signal which is stored therein is erased inresponse to transmission of the next-following signal from 107. Thesignal which is transmitted to the input a of the flip-flop 123dominates, i.e., it is not erased in response to simultaneoustransmission of a signal to the input b of 123. Thus, the output c ofthe flip-flop 123 transmits signals at intervals, and such signals areamplified by the amplifier 124 prior to energization of theelectromagnet 71 for the stop 4. The electromagnet 71 then moves thestop 4 against the opposition of the return spring 126. The position ofthe stop 4 in energized condition of the electromagnet 71 is shown inFIG. 1. Thus, the intercepting device 3 supports a non-inverted pad 104with the binder 103 located at the leading end of such pad and the rearedge face of the pad abutting against the stop 4. The stop 4 is locatedin the front end position (rightmost position) which means that the pad104 on the device 3 is not in exact register with the uppermost pad 104of the stack of pads on the platform 6. Consequently, when the device 3is withdrawn to the left and allows the intercepted non-inverted pad 104to descend, the binder 103 of such pad is located to the right of thepad 104 therebelow. In other words, the pads are neatly stacked becausethe binders 103 are not located between the covers or outermost sheetsof the neighboring pads 104.

When the device 3 intercepts an inverted pad 104 whose binder 103 islocated at the trailing end, the electromagnet 71 is deenergized and thespring 126 is free to maintain the stop 4 in the left-hand end position(i.e., to the left of the end position which is shown in FIG. 1).Therefore, when the device 3 is retracted in a direction to the left,the binder 103 of the inverted pad 104 is arrested by the stop 4 andsuch pad descends onto the previously deposited (non-inverted) pad insuch a way that the binder 103 is located to the left of the padtherebelow. The manner in which the pads on the platform 6 are stackedis clearly shown in FIG. 1, i.e., the binders 103 of successive pads arerespectively located at the right-hand and left-hand sides of the stack.The spring 126 is free to maintain the stop 4 in the left-hand endposition because the signal which is transmitted to the input b of theflip-flop 123 erases the signal at the output c in response totransmission of each second signal from the photocell 107 via shiftregister 118.

The extent to which two neighboring pads 104 of the stack on theplatform 6 are shifted with respect to each other (as considered in thedirection of delivery of pads by the conveyors 8) at least equals 2Dwherein D is the diameter of a binder 103. This invariably insures thatthe binders 103 cannot interfere with predictable stacking of pads 104on the platform 6. In fact, all leaves of each pad 104 can be located inhorizontal planes if the lowermost pad 104 of a stack on the platform 6is an inverted pad and is deposited in such a way that its binder 103 islocated to the left of the left-hand edge face of the platform 6.

The detector 96 monitors the height of the stack on the platform 6. Thearrangement may be sure that the detector 96 transmits a signal when itis physically contacted or closely approached by the uppermost pad 104on the platform 6. Such signal is transmitted to the brake 93 viacircuit 94 which disengages the brake for a short interval of time so asto allow the platform 6 to descend by gravity with attendantdisplacement of the support 92 and chain 91 (the clutch 97 is disengagedso that each release of the brake 93 enables the support 92 to descendby gravity under its own weight as well as owing to the weight of theplatform 6 and the stack of pads 104 thereon). Thus, the platform 6 candescend stepwise in response to intermittent release or disengagement ofthe brake 93.

The desired number of pads 104 in a complete (fully grown) stack on theplatform 6 is selected by appropriate setting of the counter 119. Thus,and assume that the output c of the counter 119 transmits a signal inresponse to reception of n signals from the photocell 107, the signal atthe output c of the counter 119 resets this counter to zero (see theinput b) and is further transmitted to the first stage of the shiftregister 117. The signal which is transmitted by the output c of thecounter 119 is propagated from stage to stage of the shift register 117by pulses which are generated by the proximity detector 112. When thesignal reaches the last stage of the shift register 117, the stack onthe platform 6 contains a preselected number (n) of pads 104; theamplifier 121 then energizes the clutch 97 which rotates the disk 81 andthe cam 82 in a clockwise direction, as viewed in FIG. 1. The clutch 97causes the parts 81 and 82 to complete one revolution in response totransmission of torque via main drive shaft 23 and transmission 98. Thedisk 81 pivots the bell crank lever 78 which causes the trolley 76 tomove the stack removing pusher 72 forwardly (to the right) and back toits retracted position, whereby the prongs of the pusher transfer thefully grown stack of pads 104 onto the table 7. The level of the upperside of the base plate of the table 7 is then flush with the level ofthe upper side of the base plate of the platform 6 so that the lowermostpad 104 of the fully grown stack can be readily transferred onto thetable 7. While the pusher 72 moves in a direction to the right, asviewed in FIG. 1, its auxiliary platform 73 receives and supports thepad 104 which is delivered during movement of the pusher from itsretracted position. The thus intercepted pad 104 descends onto theplatform 6 in response to retraction of the pusher 72. In the meantime,the platform 6 is lifted to its uppermost position by the cam 82 whichcauses the roller follower 83 and rod 87 to lift the support 92. Whenthe roller follower 83 completes the tracking of the radially outermostpoint of the peripheral surface of the cam 82, the platform 6 is allowedto descend through a certain distance (due to provision of the flat 82Aon the cam 82) until arrested by the brake 93 in response to a signalfrom the circuit 94. This will be readily appreciated since the circuit94 transmits a signal for temporary disengagement of the brake 93 whenthe platform 6 or a pad thereon is sufficiently close to the detector96. The apparatus is then ready to continue with accumulation of a freshstack (the lowermost pad of the fresh stack is the pad which istransferred from the auxiliary platform 73 in response to retraction ofthe pusher 72 to its normal or starting position).

If the delivery of pads 104 is interrupted, the turn-around ororientation changing device 2 remains in the position of FIG. 1 or 3until the next pad arrives into the range of the pocket 38, either toadvance past the device 2 without inversion or to be inverted inresponse to rolling of the gear 42 along the toothed rack 43. This isdue to the fact that the inverter 114 transmits a signal in the absenceof a signal from the photocell 107 so that the AND gate 113 receives twosignals (one from the inverter 114 and the other from the proximitydetector 112) and disengages the clutch 53 via amplifier 116. In otherwords, the clutch 53 interrupts the transmission of motion from thetransmission 54 to the gears 51, 52 when the path for the pads 104exhibits a gap of excessive width, namely, a gap whose width isindicative of the fact that one or more pads are missing.

The photocell 107 also ceases to transmit signals to the input a of thecounter 119 and to the first stage of the shift register 118 whenever apad 104 is missing, i.e., the electromagnet 71 remains energized ordeenergized and the stop 4 remains in its previously assumed positionuntil the next pad moves along the path portion below the photocell 107.Since the pusher 72 is controlled by the counter 119 which, in turn,receives signals from the photocell 107, the number of pads 104 in afully grown stack on the platform 6 is the same regardless of whether ornot the delivery of pads was temporarily interrupted.

As a rule, the rate of delivery of pads by the conveyors 102 isconstant, i.e., the conveyors 102 and 8 transport a file of equidistantpads 104 so that the device 2 can be actuated at regular intervals toinvert selected pads, and the moving means 71, 126 for the stop 4 can beoperated at regular intervals to change the position of the stop priorto or upon completion of each inverting step. This insures thatsuccessively intercepted and deposited pads 104 are properly staggeredwith respect to each other, as considered in the direction of transportof pads toward the stacking platform 6, i.e., that the binders 103 neednot be overlapped by and need not overlap the outermost sheets or coversof the neighboring pads 104. Consequently, all sheets lie in planeswhich are parallel to the upper side of the base plate of the platform6. The control system 106 synchronizes the operation of moving means 71,126 for the stop 4 with the operation of actuating means 55 for thedevice 2 so that the stacks are built automatically and with a highdegree of accuracy and reproducibility.

The provision of means for interrupting the operation of moving meansfor the stop 4 and the operation of actuating means 55 for the device 2is desirable because the file of pads 104 which are fed by the conveyors102 and are thereupon transported by the conveyors 8 invariably exhibitsone or more gaps regardless of whether the machine which processes thepads ahead of the conveyors 8 is automatic or semiautomatic. Thepresence of gaps at more or less frequent intervals is attributable tomany factors. For example, if the machine which processes the pads aheadof the conveyors 8 is semiautomatic, the presence of gaps isattributable to the failure of workmen to deposit finished pads atregular intervals. Furthermore, and regardless of the (automatic orsemiautomatic) nature of processing machines, it is necessary or highlydesirable to remove maculated pads. In the absence of means forinterrupting the operation of actuating means for the device 2 and/ormeans for interrupting the operation of means for moving the pad 4,removal of a single maculated pad could result in the formation of astack wherein at least two neighboring pads would have the sameorientation. This would place the binders 103 of such pads into aposition of overlap so that the entire stack would slope downwardly in adirection away from the immediately adjacent overlapping binders andsuch binders could interlock to prevent orderly removal of correspondingpads when the stack is to be broken up in a store or anotherestablishment. Signals which are generated by the photocell 107 ondetection of the absence of a pad (and more accurately stated thosesignals which are generated by the monitoring means including thephotocell 107 and the associated inverter 114) are used to influence theoperation of actuating means 55 for the device 2 and the operation ofmeans 71, 126 for moving the stop 4 so that the absence of one or morepads from the file which advances toward the stacking device 6 cannotprevent a predictable stacking of successively delivered pads.

It is clear that the apparatus could be provided with two monitoringmeans, namely, a first monitoring means which would generate signals fortransmission to actuating means for the device 2 on detection of theabsence of one or more pads, and second monitoring means for generationof signals which would be transmitted to moving means for the stop 4 ondetection of the absence of pads 104. However, the illustratedarrangement which employs a single monitoring means is preferred at thistime because it is simpler, more compact and just as (or even more)reliable than two discrete monitoring means.

The device 2 constitutes a very simple but effective and compact meansfor changing the orientation of selected pads 104 of the succession ofpads in the path which is defined by the conveyors 8. In certainpresently known apparatus, the orientation changing device comprises asystem of pulleys for a belt and means for pivoting the pulleys about afixed axis. A drawback of such orientation changing devices is that theycan operate properly (i.e., without affecting the positions ofnon-inverted commodities) only when the commodities are supplied atrelatively long intervals and the commodities are advanced at arelatively low speed. If the speed of transport of commodities isincreased, the conventional orientation changing device is likely tochange the position of neighboring non-inverted commodities, e.g., insuch a way that a file of discrete pads is converted into a scallopedstream wherein neighboring pads partially overlap each other. Thisinterferes with predictable stacking of pads and renders it impossibleto invariably invert each second pad of the scalloped stream. Suchdrawbacks of the conventional orientation changing device are attributedto the fact that the device is pivotable about a fixed axis. Therefore,if the pads of the file are close to each other, the inverted pad isinvariably overlapped by the next-following non-inverted pad before theinverted pad leaves the device.

The improved orientation changing device 2 constitutes an improvementover the just described conventional devices because it renders itpossible to change the orientation of each n-th (e.g., each second) padwith a heretofore unmatched degree of predictability. This is attributedto the fact that the carriage 27 for the pocket 38 is movable back andforth in and counter to the direction of transport of pads 104 along thepath which is defined by the conveyors 8. Thus, the pocket 38 can movetoward an oncoming pad 104 which must be inverted, and the pocketthereupon moves in the direction of transport of pads on the conveyors 8during inversion of the pad therein. This insures that the device 2 canproperly invert pads which are closely adjacent to the preceding andnext-following pads and also that the pad which follows a freshlyinverted pad does not overlie the latter, i.e., such pads do not form ascalloped stream. The improved orientation changing device is simple,compact and reliable. Moreover, its actuation can be readilysynchronized with actuation of other units or components of theapparatus because the conveyors 8 (or more accurately stated theconveyor portions which are located between the pulleys 11, 13 and aretrained over the pulley 12) form part of the device 2. The likelihood ofinterference between pads which are being inverted and the immediatelypreceding and following pads is reduced or eliminated because the pocket38 moves counter to the direction of transport of pads on the conveyors8 during entry of a pad into its interior and such pocket moves towardthe stacking platform 6 as soon as it receives a pad, i.e., as soon asthe pad therein is certain to share the pivotal movement of the pocketabout the axis of the reciprocating shaft 33. Therefore, the distancebetween the identically oriented pads 104 upstream of the device 2 isnot much different (i.e., not much more uniform) than the spacingbetween the alternating inverted and non-inverted pads between thedevice 2 and the stacking platform 6.

The placing of the axis of the shaft 33 into the region of the openings39 (preferably substantially midway between the pulleys 11 and 13)reduces the likelihood of uncontrolled movements of pads which arereceived in the pocket 38. In other words, the pads remain in the pocketduring inversion and are not likely to wobble or to perform otherunpredictable movements while the pocket 38 pivots from the position ofFIG. 1 or 2 to the position of FIG. 3.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can, by applying current knowledge,readily adapt it for various applications without omitting featuresthat, from the standpoint of prior art, fairly constitute essentialcharacteristics of the generic and specific aspects of my contributionto the art and, therefore, such adaptations should and are intended tobe comprehended within the meaning and range of equivalence of theclaims.

I claim:
 1. In an apparatus for manipulating substantially flatcommodities, such as note books or pads, the combination of means fortransporting a succession of commodites in identical orientation in apredetermined direction and along a predetermined path; orientationchanging means adjacent said path and actuatable to change theorientation of selected commodities in said path, said orientationchanging means including a pocket having an opening and being movablebetween a first position in which said opening is located in the path ofan oncoming commodity and a second position in which said opening allowsthe commodity to leave said pocket by moving in said direction; andmeans for actuating said orientation changing means including means forpivoting said pocket about an axis which is substantially normal to saiddirection and means for moving said pocket and said axis in saiddirection during movement of said pocket from the first to the secondposition and counter to said direction during movement of said pocketfrom the second to the first position.
 2. The combination of claim 1,wherein said transporting means comprises at least one endless flexibleelement.
 3. The combination of claim 1, wherein said pivot axis islocated in the region of said opening.
 4. The combination of claim 1,wherein said pivoting means includes means for causing said orientationchanging means to invert each second commodity of said successionthrough an angle of approximately 180 degrees.
 5. In an apparatus formanipulating substantially flat commodities, such as note books or pads,the combination of means for transporting a succession of commodities inidentical orientation in a predetermined direction and along apredetermined path; orientation changing means adjacent said path andactuatable to change the orientation of selected commodites in saidpath, said orientation changing means including a pocket having anopening and being movable between a first position in which said openingis located in the path of an oncoming commodity and a second position inwhich said opening allows the commodity to leave said pocket by movingin said direction, said transporting means comprising at least oneendless flexible element and said orientation changing means furthercomprising pulleys for said flexible element, said pulleys being mountedin said pocket to confine successive portions of said flexible elementto movement first into and thereupon from said pocket so that saidelement entrains an oncoming commodity into said pocket by way of saidopening in the first position of said pocket and from said pocket viasaid opening in the second position of said pocket; and means foractuating said orientation changing means, including means for pivotingsaid pocket about an axis which is substantially normal to saiddirection.
 6. In an apparatus for manipulating substantially flatcommodites, such as note books or pads, the combination of means fortransporting a succession of commodities in identical orientation in apredetermined direction and along a predetermined path; orientationchanging means adjacent said path and actuatable to change theorientation of selected commodities in said path, said orientationchanging means including a pocket having an opening and being movablebetween a first position in which said opening is located in the path ofan oncoming commodity and a second position in which said opening allowsthe commodity to leave said pocket by moving in said direction; andmeans for actuating said orientation changing means including means forpivoting said pocket about an axis which is substantially normal to saiddirection, said pivoting means comprising a gear secured to said pocketand a stationary toothed rack meshing with said gear, said actuatingmeans further comprising means for alternately rotating said gearclockwise and counterclockwise.
 7. The combination of claim 6, furthercomprising prime mover means for said transporting means, said means foralternately rotating said gear comprising a crank drive deriving motionfrom said prime mover means.